West Yost provided preliminary and final design for one of the
largest cured-in-place-pipe (CIPP) projects in the U.S., to
rehabilitate approximately 44,700 feet of sewer using an
innovative liner material (iPlus®). The trunk line is 42-inches
to 60-inches in diameter and runs under major streets,
residential backyards, creeks, a freeway, through protected
wetlands, and near many homes, schools, and businesses.
Approximately 3,000 feet of the Franklin Trunk was also included
in the project. The rehabilitated portion of the Franklin Trunk
was 33-inch diameter sewer reinforced concrete pipe.

This award-winning project involved successfully addressing
significant engineering and construction challenges. Significant
engineering challenges included full sewer continuous
operations during construction, complicated bypass planning and
implementation, and a sizable crossing under Highway 99, where
two trenchless technology alternatives were evaluated including
bore and jack, and horizontal directional drilling. Community
relations were also a significant issue on this project. West
Yost worked with SASD staff in communicating with the public,
addressing noise issues, and evaluating trucking limits to reduce
public impacts.

SASD’s Central Trunk sanitary sewer serves the southeastern
portion of Sacramento, conveying wastewater to the Sacramento
Regional Wastewater Treatment Plant (SRWTP). The eight-mile
Central Trunk sewer was constructed in 1961 of unlined reinforced
concrete pipe. After nearly 50 years of service, the sewer was
severely corroded. Restoring the structural stability of the
Central Trunk with minimal decrease in capacity was the project’s
primary goal. SASD aimed to meet this goal in a cost-effective
manner with as little disruption to the community as possible,
and therefore chose CIPP as the single method of rehabilitation.

The award-winning Central Trunk Sewer Rehabilitation
Project, to rehabilitate approximately 44,700 feet of
sewer, is the largest cured-in-place-pipe (CIPP) project in the
country.